Re: Re: Remotely exploitable crash in dhcpcd
Roy Marples
Mon Jun 26 11:07:28 2017
Hi Jason
On 25/06/2017 17:48, Jason A. Donenfeld wrote:
> Both interfaces now get both address, which is great.
>
> However, I've found two small bugs in this initial stab at the implementation:
>
> - eth0 is metric 200
> - wlan0 is metric 300
> - set eth0 up --> eth0 gets 10.10.10.100
> - set wlan0 up --> wlan0 gets 10.10.10.100
> - unplug eth0 --> ARP sent wlan0 so smooth transition
> - plug eth0 --> ARP sent on wlan0 instead of on eth0, so transition is
> not smooth, until gateway does its own ARP
>
> and
>
> - eth0 is metric 200
> - wlan0 is metric 300
> - set eth0 up --> eth0 gets 10.10.10.100
> - set wlan0 up --> wlan0 gets 10.10.10.100
> - unplug wlan0 --> ARP sent on eth0 even though it isn't needed, I think
> - plug wlan0 --> ARP sent on wlan0, which is incorrect, so pings of
> eth0 get interrupted temporarily
I can't replicate this.
If you run `dhcpcd -dB4` in a window, you'll see debug logs across all
interfaces as they happen.
If you do that and go through the above motions, do you see ARP
announcements on the correct interfaces? If not, please post your
dhcpcd.conf, if so can you verify they are leaving the correct interface
via tcmpdump?
Also, what kernel version are you running?
Roy
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